You kind of have to give it up for Sally Field. Despite the fact that Hollywood offers an extremely limited range of roles to any actress over the age of 35 (and Meryl Streep and Glenn Close nab most of them), she’s continued to have an amazing career well into her 60s. In our youth obsessed culture, that’s a real accomplishment.

I’ll admit that the media doesn’t help much with this. Entertainment sites (this one included) tend to focus on young up-and-comers, to the detriment of people who’ve been turning in solid work for years. Until someone like Sally Field comes along and blows us away with an amazing performance, that is. Then everyone remembers that you get better at your craft as you get older. That’s just math!

I went into the film knowing about as much about Mary Todd Lincoln as any product of the American educational system; she was Honest Abe’s wife, she had three sons who died before she did, and I very vaguely remembered something about her mental health issues. But basically, I knew she was Abraham Lincoln’s wife. Field’s performance manages to educate us about Mary Todd Lincoln, even as she adds an emotional depth of her own to the character. (It’s impossible for us to truly know Mary Todd Lincoln, but she fills in the blanks nicely.) From the very start of the film, in which Lincoln tells her about a dream he had, she presents Mary (or “Molly” as her husband called her) as a worthy companion to President Lincoln. She also helps us find a way into who Lincoln really was, not as a historical figure, but as a man. The scenes with Mary and little Tad allow him to take a break from all the political maneuvering and exist as a private citizen.

The film opens in 1865, just three years after Mary and Abe lost their son Willie to typhoid fever. Although she’s at times been dismissed by history as “mad,” and there’s a chance she’d be diagnosed with something official, were she alive today, she inhabits the depths of Mary’s motherly grief in a way that feels genuine and un-melodramatic, even as things are getting super dramatic. Like all biopics of great figures, this film is necessarily a work of fiction, but the relationship Field and Day-Lewis construct is one that makes intuitive sense. Lincoln was a brooding and tortured man, as well as being incredibly smart, and it stands to reason that he’d choose a similarly complicated partner. One of the most poignant parts of the movie, for me, is the scene when they’re fighting about her “mad” behavior following Willie’s death and Lincoln tells her (and us) that he wishes he could express those very emotions, but he can’t because he has to be strong for the country. In that way, she functions as a kind of mirror to Lincoln’s darkest feelings.

But she’s not all doom and gloom, either. In the party scenes, she shows Mary’s charm and wit, as well as her ability to handle prickly figures like Thaddeus Stevens (played very well by Tommy Lee Jones). As for the age thing, I think Field more than passes for a 45-year-old woman in the Civil War era; whatever dark magic she’s doing on herself to stay young didn’t exist back then. Mary Todd Lincoln died 63, and daguerrotypes show her looking quite a bit older than the average 45-year-old Hollywood actress at 45. (It’s also notable that Field gained weight for the role.) And her final conversation with Lincoln about where they’d like to travel after he’s done being president is equal parts heartwarming and heartbreaking, shot through with tenderness and shared history. For all their issues, Molly and Abe cared very much for each other, or at least that’s the story the film very believably presents.

It doesn’t escape me that Mary wonders aloud in this final scene what history will make of her, and whether folks will see her as anything other than a hysterical ball and chain around a great man’s neck. If Mary Todd Lincoln did indeed wonder this, and if she were alive today, I’m fairly confident she’d be happy with Sally Field’s nuanced portrayal of her. My only quarrel with any of it is that she didn’t get more screen time.